


An Agreement Between Two Princesses

by darkrestorer



Category: Fire Emblem Series, Fire Emblem: Kakusei | Fire Emblem: Awakening
Genre: Cuckquean, F/M, Humiliation, Porn With Plot, Submission, Voyeurism
Language: English
Status: Completed
Published: 2020-11-03
Updated: 2020-12-01
Packaged: 2021-03-08 22:41:20
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 9,284
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27364441
Author URL: https://archiveofourown.org/users/darkrestorer/pseuds/darkrestorer
Summary: Lucina and Morgan's sex life was stagnating. While trying to come up with a solution, Lucina encountered her sister, Cynthia. Lucina sought help from the pegasus knight, only to find out that what she actually yearned was to have her own sister to bed her own boyfriend.
Relationships: Lucina/Marc | Morgan/Cynthia
Kudos: 25





	1. Chapter 1

The room was illuminated by a single candle sitting on top of a dresser, one that was being bumped by the old bed Lucina was lying on top of. She smiled at her lover, Morgan. With hands planted on either side of her hips, his nude form was lightly coated by a blanket of sweat beads. Although majorly skinny, he had robust muscles across his chest, something she found quite attractive. He pumped his hips with a gentle but strong force as he thrust his cock inside her wet cunt. Small pleasurable jolts shot through her lower regions towards her.

"Mmm….Morgan…" Lucina moaned as she watched him do the usual to her, hands limply sprawled at each side of her head. Her azure hair was spread across the light feather mattress, shifting with each sliding of her lithe body.

Morgan panted, heavy breaths following his eager thrusts until she felt him start to raise up his pace. "Lucina….I'm cumming….ahh…."

She wrapped her arms around his neck and pulled him close for a sweet kiss. As she felt him shot his warm seed start to rush out, he pulled out just in time and sprayed it all over her abdomen, right before she reached her own climax. "Mmpf.. hahhhh…" She pressed her lips against his again and again until the heat on her face subsided along with the high from her orgasm. Morgan rolled off away from her, his sharp breaths turning into a sigh of relief. "That was good, Morgan, as always," she said to him with a smile.

He smiled at that, his chest rising and falling. He laid on his back and watched the ceiling of his apartment for a little while. "Yeah…." He trailed off.

"What's the matter?" She turned her body to the side. The small puddles he made on her stomach started running towards the covers, but she could care less about that.

"Well….How do I say this?" There was a brief pause as Morgan hesitated. "I love you, Lucina and sex with you is always good and all, but I can't help but feel something missing. Sorry if this sounds like I'm let-down or something. I think I'm just under a slump."

"A slump, huh?" Lucina laid back again, pulling the covers over her naked breast. "I think I'm feeling the same, honestly. After the first few months, something feels amiss with our nightly activities."

"Yeah, I thought the same, too." Morgan looked her in the eyes as he embraced her. "I'm sure this will disappear soon enough."

Lucina leaned her head against him when he drew closer, resting his chin against her shoulder. In moments, he fell asleep, leaving her to worry about their situation alone. She didn't mean to make him anxious, which was why she didn't tell him that she had sensed this slump even a while back. Perhaps she felt it more strongly than him.

The sex just wasn't as arousing or exciting as it used to be back during their first month, and even before that during their first time. They used to be so impatient, waiting for night to fall each day so they could hide away in Morgan's room. But now there was none of that. She needed to change that somehow. She needed to come up with ways to add spice to their sex life or else it would threaten her relationship with Morgan.

She worried about it all night long until she fell asleep and the candle in his room died out.

* * *

Ylisse's great castle walls were draped with a good amount of sunlight as Lucina passed through the great gate. She couldn't bear to watch, much less admire the peace and tranquility the kingdom was experiencing away from the throes of war. Morgan had left early for a meeting with Ricken and her father related to the country's military affairs. She had her schedule completely open, so she had no idea what to do with herself but sank into her thoughts about last night.

She sighed under the stone corridors, just a short stone's throw away from the main hall. She had thought about going to her father, but she didn't know if meeting him in the presence of Morgan was the right idea, so she changed directions to the open fields of the outer training ground. Maybe giving Falchion a couple of swings and practicing her footwork would calm her senses.

As she left the cobblestone path and set foot on the grass, she caught sight of her sister, Cynthia, performing a series of well-executed jabs with her spear. Her sister had gotten better at it as well as riding her pegasus in extreme heights.

Resting her spear on her shoulder, Cynthia wiped the sweat off her forehead and breathed out. A second later her eyes met Lucina's, and she gave an energetic wave. "Lucina! Heyyy!" She smiled.

"Hello, Cynthia." Lucina shortened their distance and stopped right in front of the pegasus knight. "Are you training here all by yourself?"

"Yeah, the rest of the girls are out on missions, so it's just me here." Then her smile turned into a sly grin. "How about you? How's the lovey-dovey couple these days?"

"We are doing fine." Lucina tried her best not to sound troubled and switched the topic. "Want to spar for a bit? I've been looking for a good workout to distract myself."

Cynthia pursed her lips, possibly of suspecting her of something, yet it disappeared all the same. She beamed and lowered her spear, gabbing it with both hands "Sure! Why not?"

There was not a soul around them as Lucina drew her blade and commenced the practice bout. She forgot all about her misgivings the moment that Cynthia's spear came crashing down, and she blocked it with her sword. She was impressed with her sister's growth, and not just with the way her body swelled in all the right areas over the years. She'd be jealous of her sister if she wasn't so blessed. Still, it was easy to keep up with Cynthia in terms of combat. The two never slacked with their training, but Lucina knew her sister's moves like the back of her hand.

* * *

Morgan strode across the courtyard, stretching his arms high up to expel the restlessness he got from waking up early. The meeting had been postponed, so he was left with absolutely nothing to do. Lucina had been on his mind lately ever since he saw how worried she seemed last night, and so his mind was a bit preoccupied as of late.

He thought about buying her something later to cheer her up some when he saw a series of flashes reflecting the abundant sunlight of this morning. Curious, he drew close, leaving the cobblestones for the softer grass field, and saw his girlfriend having a sparring session with her sister. Not wanting to interrupt, he took a spot on the grass away from the two and watched with fascination. He always liked seeing the two display their skills. It's a nice treat since their maneuvers and attacks were like art.

Feeling the soothing breeze brush his cheek, his gaze wandered after a while until they landed on Cynthia. He couldn't help but examine the girl's figure from the side. She had quite the buxom good looks, although she was quite the clumsy air-head. Unlike Lucina, Cynthia was quite gifted in the chest area. He had no way of fending off the urge to stare at those rather impressive melons, not when she was wearing such a tight tunic. It was long and blue, almost the same color as her hair, with a single large stripe going down to her skirt. He thanked the gods her only armor was above her shoulders and her boots. Her boobs were rocking all over the place as she made swift, energetic leaps and thrusts. Her personality matched her movements to a tee. She was a complete contrast to the stern and serious Lucina.

Watching the flawless skin of her underarms as well as the side of her boobs which her tunic strained to cover but to no avail got him so worked up that he failed to realize he was checking out his own girlfriend's sister.

He shook his head and poured all his focus on Lucina instead. As much as the pegasus knight got his imagination going, she was still Lucina's sister, and it was wrong to lust over her in his girlfriend's presence.

It didn't take long for them to notice him after they ended their session. He stood up as the two approached.

"Morgan!" Lucina was the first to greet him. She went and pecked him on the cheek before stepping back. "What are you doing here? I thought you had a meeting with my father."

"Hi, Lucina. It was delayed, so I took a stroll until I saw you two." He turned to the younger sister as she called out.

"Hey, Morgan. Haven't seen you in a while." Cynthia went right up to Lucina's side. For some reason, she looked him up and down before smiling. "Did you get taller? 'Cause you're more handsome than I remembered."

"No, I'm still the same old Morgan." Feeling nervous under her penetrative gaze, he scratched the back of his neck.

Lucina interrupted them with a cough, seemingly sensing something amiss with the conversation. "Morgan here has definitely built up a solid frame since he took up my swordsmanship lessons."

"I guess," Morgan chimed in. "Anyway, I hope you don't mind me appearing out of the blue and cutting your practice short."

"Of course, not silly." Cynthia's eyes as she smiled at him was bright and shining. "You are always welcome to watch me practice, Morgan. How about I give you a few lessons too, just the two of us."

"Cynthia..." Lucina shot her a critical look. "Are you trying to flirt with my boyfriend?"

Morgan felt a cold sweat forming around his neck.

"It's just a joke! Geez, Lucina, you know I would never do that to you." She spun her spear around. "I think I'm going to resume my training and leave you two lovebirds alone."

Lucina let out a sigh as her sister skipped away, still brimming with energy. "Let's take a seat over there, Morgan."

"Can't handle all that energy, huh?" Morgan teased as she followed her to an untrodden part of the grass.

"I feel old just by standing near her." She slumped down and took her waterskin out for a drink.

Morgan sat next to her and watched the pegasus knight do a series of drills. She tripped a couple of times but got up and patted her skirt immediately as if it were nothing.

"So, what are we going to have for dinner tonight?" He heard Lucina ask him.

"Hmm...how about we eat out? We can find someplace we haven't gone to before and try their best dish," Morgan said after finding a quick option she was sure to take.

"Sounds good." He heard her shuffling before taking a quiet break.

Morgan saw Cynthia bury the butt end of her spear into the ground to get it to stand up as she straightened her back and caught her breath. With all the flurry of jabs and thrusts that she made from her drills, it was unsurprising that she was covered with sweat. Then something that Morgan couldn't help but focus on occurred. The second princess went and unfastened the top button of her tunic. He gulped, seeing the large tracts of land being unveiled through her open collar. It was a wonder how her clothes could keep it from spilling the rest out.

"That sister of mine. She's always so unguarded." Lucina sounded disappointed.

But Morgan was actually thankful for Cynthia's innocence. He caught himself before he could utter a word that would get him a dirty look from her girlfriend. He couldn't blame himself though, Cynthia was quite the looker. Before anyone of them noticed his perverted behavior, he diverted his attention elsewhere while keeping the pegasus knight at the corner of his eye.

* * *

Lucina sighed, setting her waterskin down. Cynthia was so thoughtless, showing off skin when she knew there were people in her midst. She was about to stand up and berate the airhead when she noticed Morgan went completely silent, sucking in his breath. _No way. Is Morgan…. gawking at my own sister?!_ There was no doubt in her mind that those brilliant eyes of his were glued to her sweating figure and the massive orbs she was packing in that old top of hers. Moreover, her eyes drifted down, and she couldn't believe what she just saw. He was hiding a massive lump underneath his pants, a sight she had not seen in a long while. His cock throbbed and strained painfully against his clothing, yearning for her own flesh and blood, for the maiden whose clumsy demeanor was overshadowed by a buxom figure that could turn heads and put her position as the elder sister beneath in terms of charm.

She should have been angry, but she wasn't. There was a pang of jealousy, true, but something else was surfacing. Something which got her feeling pleasurable rush down her loins. She didn't get up from her seat or break Morgan's opportunity to salivate over her sister's gorgeous body. She just stayed there and let him do as he pleased, be it fantasizing over Cynthia or not.

This feeling was doubled now that she thought about how Cynthia flirted with him earlier. There wasn't any doubt that she fancied him. Even back during the war she would always come to his side and chat him up, trying to get closer to him. If Lucina hadn't got in between them, Cynthia would have ended up with Morgan.

She couldn't tell exactly what this feeling she was experiencing. It's as if she was aroused by the sight of her boyfriend drinking in the sight and being turned on by another woman.

Her stupor was broken by Morgan standing up.

"I….I need to go," he said after brushing his pants. "Ricken might be looking for me now."

"O-ohh. Take care, Morgan."

"See you later, Lucina. Let's meet up when I'm done with the meeting." He smiled at her before vanishing into the courtyard.

Lucina felt all tension leaving her. She turned her attention back to her sister and saw the girl heading back.

"Morgan left already?" Cynthia gazed around.

"Yeah, he said needed to get back." Lucina's legs were wobbling when she stood up, but then she noticed Cynthia's indecency again and decided to point it out. "You really should be more conscious of your appearance, Sumia." She pointed at her sibling's chest.

"Oopsss…" She stuck out her tongue, trying to look cute, before fixing up her tunic. "Ehehe I didn't even notice."

Lucina fiddled her fingers for a minute, fighting her own doubts and questioning herself what she should do, while Cynthia drank her refreshment. "Hey, Cynthia, are you busy after this?"

"No, I'm totally free for the rest of the day. What's up?"

"Well, it's just that I need someone to talk to. Can we talk somewhere private?"

Cynthia looked thoughtful for a moment. "How about the pegasus knights' barracks? There's nobody there at the moment."

"That's fine. Shall we go?"

"Sure, I'll lead the way." Her sibling strode off. Lucina followed while lost in thought.

When they entered the barracks, Lucina saw the place was indeed empty save for the equipment and armor neatly stashed aside, proving how orderly the group can be. There were a number of clothes racks, grinding stones, leather harnesses, workbenches, and a rest area complete with tables and chairs. There was a place where the pegasus knights could gather together and have a tactical briefing. After grabbing a dry rag from her oak trunk, Cynthia took a seat on a long bench with Lucina sitting close to her.

"Been a while since we talked like this huh, Lucy." Cynthia leaned back against the support of her arms. "It's nice having these private moments that we can share."

"Indeed." Lucina smiled. "And you've been fitting along well with the rest of your group. You're not making trouble for them, are you?"

"Psshh, of course not!" Her clumsy sibling laughed. "Things are going so well with the missions that I'll get to hero status in no time. I'll keep on growing until I am deemed worthy of that title."

"Well, Morgan was checking you out, so your growth is well monitored."

"Wait, hold up. Morgan was checking me out?!"

Lucina intended for it to be an offhand comment, but clearly, it was a mistake. "Yeah," she said before she could think twice. "He was rather fond of your….assets."

Hearing that, Cynthia chuckled. "I didn't know Morgan was such a perv. He always struck me as the innocent type. But I'm flattered! He can check me out any day."

Lucina gulped at that statement. Cynthia could be so unhinged at times. "You didn't do it on purpose did you?" She eyed the pegasus knight carefully.

"No, why would I?" Cynthia sounded earnest. "Morgan is so obviously into you no matter what kind of moves I make."

"Yes, I see your point."

There was a pregnant pause as Lucina's mind wandered off. A few moments later, she decided to broach the topic which had been nagging at her for a while now. "Hey, Cynthia, do you fancy Morgan by any chance?"

The younger princess pursed her lips. "That's a rather difficult question to answer for me, Lucina."

"I see... Then…" Lucina hesitated. She couldn't believe what she was going to say next. "What if ...hypothetically he asked you to sleep with him, would you?"

Cynthia's eyes grew wide, shocked by that inquiry. She looked down as her expression turned serious. "I'd decline him since that would be robbing him from you."

"What if I give you my consent?"

"Lucina, what's all this about?"

The swordswoman toyed with her fingers on her lap, not feeling dread but arousal. "You see, Morgan and I have been experiencing a bedroom slump," she quietly said while Cynthia listened in, not saying a word. "Sex hasn't been exciting or passionate as before. It's become nothing more than a routine, and I'm afraid if this keeps on, we might run into a snag in our relationship."

"And you think that by adding a third member to your bedroom, you'll be able to add spice into your life?"

"It's just as you say." Lucina nodded.

"But what gave you the bright idea of inviting me?" Cynthia's gaze was nothing short of intense.

Lucina felt herself shrink back. "I have to confess. Earlier while Morgan had his eyes on you, he pitched a tent in his pants, and it actually aroused me. Seeing him getting turned on by you gives me such a rush. It's nothing that I've felt before, even compared with my first time with Morgan. I got wet just by imagining him thinking lewd thoughts about my own sister. You obviously have a thing for Morgan, so I thought you would likely be okay with sleeping him."

"Wow, Lucina." Cynthia appeared to be unable to believe what she was saying. "I would never expect you to suggest this kind of racy play. Yes, you are right. I do find Morgan hot, but sleeping with him? Well, I've never actually considered it since he's been taken by my elder sister. Are you sure you aren't sick or stressed out?"

Lucina swallowed something in her throat. "Yeah, I assure you I'm quite fine. Actually, I feel so energized talking about this."

"In that case, I'll tell you. If Morgan asked me and you gave us consent, then I'd jump right in and pounce Morgan. I mean, who wouldn't want a piece of that guy?" Cynthia grinned, and Lucina noticed her own hands shaking with excitement. "But before all that, Lucy, I think you should take some time and really think about it. Who knows, maybe this is just a passing curiosity you are feeling. I mean, having a threesome with my own sister and her boyfriend is such a big deal and all. Better think long and hard about this. The last thing I want is to create a rift between you two."

"No," interrupted Lucina. "I don't want a threesome."

Cynthia furrowed her brows. "What do you mean?"

"I….I want you and Morgan to do it," said the princess in a soft tone, "while I watch from the side. I won't be doing anything. Even laying a hand on Morgan is out of the question. It'll be just you two." She felt her heart beating even louder underneath her chest. A small part of her couldn't even believe she was saying such things.

"You can't be serious," gasped her sister. Although, she picked up a tiny hint of something mixed in there; she was sure of it. A slight indication that she was in a way excited by this proposal. The speck of blush forming around her cheek was proof of that.

"It's the only way I'll be able to experience the feeling I had earlier again."

"That must be one heck of a turn on you experienced," commented Cynthia thoughtfully. "And I must confess, it does get me feeling a little bit strange, in a pleasant kind of way."

"Are you turned off by the idea of having me watch?" Lucina asked, worried she might be pushing her sister. "If you're not fine with the idea...then I guess I can let you do it in private."

"Oh, oh no, I have no problem with you watching. In fact, I find that incredibly hot." A wide grin split Cynthia's pretty face. "It's the first time I've heard of such a play, but I think it sounds rather intriguing. But before anything else, take some time off and get your mind off of things, Lucy. And if you're still considering this type of scenario, talk with Morgan about it too. He has to know about all this."

"You're right. I shouldn't get a hold of myself." She finally let go of the tight grip she had on her skirt and took a deep breath.

"You can tell me your final decision until then. Alright, Lucy?" Cynthia stood up and stretched. "I must say though, Morgan is a lucky guy for having such a thoughtful girlfriend who is willing to do anything for him."

"No, I'm partly doing this for my own pleasure too," she confessed. Selfishness was a characteristic she didn't know she had.

"That may be true, but letting your boy get a taste of another woman's muff and your very own sister to boot? I would never have thought you'd have it in you."

Lucina caught something in her throat after hearing Cynthia say that. It was rather blunt, but it struck a nice pain in her. She got up and rolled her shoulders to get the stiffness out. "I still have some time before I meet Morgan. Do you want to take a walk around the castle?"

* * *

Under the bright afternoon sun, Lucina tried her hardest not to think about what she just talked about with Cynthia. It indeed might just be a passing curiosity, which would disappear as soon as she woke up tomorrow. She didn't know if she wanted it to be so, or if she wished it was there to stay. Regardless she tried getting other matters into her mind. For example, the gifts she would be presenting to Morgan's mother, Robin, on her birthday. Lucina wanted to get on the tactician's good side as much as possible after all.

It didn't take long before Morgan pushed open the large double doors and followed her father out with Ricken trailing close behind. She greeted her father, and he gave her a hug before leaving for a briefing with Frederick. Morgan and Lucina decided to head for town to see what shops were open before they had dinner.

The streets were packed full as the sun started to set. Bright lanterns hung over the roads as they passed through.

Once they finished their dinner at a small bistro that had few people but great food, they took the alleyways and headed for Morgan's apartment. Even though she promised herself that she would try to stray her thoughts away from racy things, naturally there were things outside her control.

She reclined against her favorite comfy chair inside Morgan's place, trying to relax and calm her beating heart. While she was wrestling with her own fantasies, her lover walked across the hardwood floor, organizing tomes and stacks of paper all around the place. They eventually retired to their room since it was so late. As they carried on with their small talk, Lucina thought she was going to burst.

"Hey, Morgan, can I ask you something queer?" she asked while lying on her side. She had switched out her common clothes for her glossy silken nightwear the color of the sky. Morgan liked it when she wore her nightie since it only reached above her thighs and showed off her bare legs in full.

Morgan closed his book and stashed it away underneath the bed. "What's up?" He laid on his side as well.

"Do you…" Her voice hitched. "Do y-you...find Cynthia attractive by any chance?"

Morgan choked on something and then coughed. It took him a few soft thumps on his chest before he found his voice again. "Where did that come from?"

"Oh, don't play coy with me." She smiled without meaning to. He was so cute when his composure was broken. "I saw you eyeing her so intensely earlier while she was training. It's like you just saw a naked girl for the first time. Come on, tell me. I won't get mad."

Hesitating, the boy remained silent for a minute as he tried to come up with an appropriate reply. "I do find her quite easy on the eyes."

"Enough that you'll get erect seeing her in a swimsuit?"

"Yes! But the same goes for any of the beautiful ladies in the Shepherds, especially you, Lucina." He was completely flustered when he said that to her. It almost made her want to tease him more. "Anyway, enough about that." He pulled her in closer, his hand reaching down and slipping insider nightie, cupping her ass. "Let's focus on your needs."

"Wait, I still got- Mmphhhh…." He suddenly pressed his lips against her own, cutting her off before she could ask him what he thought about a potential addition to their bedroom.

As they kissed sloppily, growing more intense by the minute, heat rose across her body, and soon, he pushed her on her back. He peppered her with kisses starting from her lips down to her chest. His fingers worked nimbly, pulling aside the side straps of her gown to pull her garment down and unveil her modest chest. Unlike Cynthia, she wasn't gifted in that area, but she had never felt insecure as Morgan always showed his appreciation for her soft lumps. He was like a man possessed as he cupped the mounds with his hands before letting his mouth ravish the crown jewels of her tits.

Lucina let out a sharp moan, grabbing his hair at the back of his head, as he ran his tongue in circles around her nipple. He was quite eager today, too eagre in fact. Her legs hooked around his waist as he started dry humping her while paying close attention to her boobs. "M-Morgan….." she inhaled shortly. Among other things that she loved about him, it was how he loved to put so much attention into her small chest. It bordered with obsession, and he was quite good at it. "Ahh...what has gotten into you?" Not that she was complaining. Her body writhed with pleasure as his hands explored her body.

"Ahhh...Oh, gods…." She moaned once more when his fingertips dipped into her folds. He massaged her breast more intensely as he multitasked, urging her body to ache for more. While he pumped his fingers inside her and drew circles with his tongue on her nipple, she cupped his growing bulge and whispered in a sweet voice, "Put it inside me...ahh..Morgan. I want your cock right this instant."

Morgan was quick to follow that command. It didn't even take a few seconds before he got his stiff manhood out and had her spread her legs.

The sex was astonishingly good, a real step up from their usual. As he stripped her of the frail raiment without her permission and escalated his endeavor to remind her who was the top in their relationship, she completely forgot what she was going to say and moaned like a whore. She didn't need to be reminded of who her pussy belonged to.

* * *

Lucina thought her worries would end after that night, but nothing changed. Days were uneventful and nights were back to normal. The slump had returned, and she had an itch that was in dire need of scratching. She didn't know she badly needed release until now, and by any means at that. Perhaps that one night showed her just what she was missing. Whether that was the case or not, it didn't change the fact that she was unbelievably frustrated.

She couldn't stop imagining a certain scenario in her mind as Morgan took her that night. It all started when her thoughts strayed too far and Cynthia's sweat-soaked figure appeared. The training ground was there, as well as Morgan. They ignored her despite her just standing within an arm's reach. Then Cynthia took the boy's hand and pulled it up to her swollen chest, a sly grin on her face. Lucina nearly reached an orgasm until she realized she was still lying in his room, getting her snatch pounded. The pleasant stupor was lost, and she was grounded to focus on Morgan and her again.

She bit her lip and paced herself along the empty castle corridors, debating whether she would go to Cynthia or retreat back to her own room in the castle. She was one corner away from her sister's door, hesitating to take one more step.

Albeit she liked that one night with Morgan, she still felt something was missing, something detrimental to them permanently getting over this stale atmosphere in their bedroom. Just one more step. If she could just reach that step, she could finally scratch that itch she couldn't reach.

Of course, she tried to distract herself by helping in training new recruits, assisting and escorting her father, and talking with other Shepherds, but her mind wouldn't get out of the gutter.

"Lucina?"

She nearly jumped back as she heard a voice followed by a feeling of someone tapping her shoulder. "Cynthia!"

The pegasus knight looked at her strangely. "You look rather unwell. What happened?"

Lucina rubbed her arm, unsure of how to phrase her thoughts well without sounding desperate. "I….I think I have decided."

"Hm?"

"I've already talked with Morgan, so I don't think there'll be any problem so…." Lucina idled for a second or two. The words were just so hard to express. "Cynthia would you be free tonight?"

"You mean…." Her sister's face morphed into one of surprise.

"Yeah, I want to go through with it. You know, what we discussed a few days ago. I thought it through, but I believe it'd be better if you were the one " But then she took a step back, filled with nervousness. "I understand if you changed your mind about all this and -"

"Hold on a minute." Cynthia grabbed her wrist before she could escape. "I'm in."

"Are you sure?" Lucina didn't try to fight the hold.

"Positive." The pegasus knight drew close, wrapping her arm around Lucina's shoulder. "Why don't we discuss the details in my room?" She grinned, and Lucina felt a fever surging through her face as she nodded.


	2. Chapter 2

The day throughout the kingdom had been sunny and full of activity. The night was even more festive as taverns filled with townspeople and travelers visiting Ylisse. A short distance away from the fanfare in a quaint corner of town was the two-floor apartment belonging to Morgan. He could hear the jolly murmurs passing by from inside the comfy home. He finished changing into a fresh set of clothes when the door gently opened and his lover stepped inside wearing a nice robe. 

“Ready for the night?” Lucina smiled as she strutted towards him, hands strategically placed on her swaying hips.

His weight made a soft creak on the bed as he sat down, enjoying her slender figure. It didn't take much deciphering to arrive at the meaning behind her lusty advance. "Sure, am." He couldn't tell her he was tired from running around all day, accomplishing errands for his mother. He dimmed the room to single candlelight using a casual hand wave and a bit of magic.

Before he knew it, she crawled on top of the bed and immediately went for his belt. He feared she'd be disappointed once she finds that his partner is still asleep, but it vanished when she licked her lips and eyed him down there, not the least bothered.

"I could use a little rub if you don't mind." He decided to turn his dilemma into playful. When she raised a brow and smirked, he knew he made the right choice.

Her fingers didn't manage to fully wrap along his length before she made a remark. "You do need a little help here, but it won't be me helping you."

A moment later a figure stood by the already open doorway. Morgan was confused and tried to focus his eyes to get the identity of this mysterious person. His jaw went slack when he found out.

"Hope you don't mind me barging in on you two, Morgan." Cynthia entered his room with a gleeful smile. 

"Cynthia?" He croaked, taking in the appearance of the pegasus knight. She wore her white and light blue uniform. Although modest, it captured her body lines perfectly. Her sudden entrance broke the relaxing atmosphere around the room and got him sitting up, limp. "What are you doing here?"

The knight stopped in front of his bed, chuckling as he covered his exposed member. "Lucina let me in. She told me you've been stripping me naked in your head, so I decided to come over here and strip for real."

The young tactician blinked once, his throat dry as a desert.

“Don’t play dumb with me.” Cynthia shot him a sultry look. “Lucina told me herself that you were sneaking glances at me while I trained, you perv. But, to be honest, knowing that you looked at me that way got me really worked up, so I couldn’t hold back when Lucina herself invited me to your little night activities.”

Morgan turned his stone-faced expression to his lover, unable to grasp what was going on. Meanwhile, her younger sister was unfastening belts around her uniform and getting rid of her boots.

"I thought it’d be nice to add a little spice to our bedroom." Lucina backed away from him, keeping a lustful gaze on him while getting off of the bed. “Don’t you think so too, Morgan?”

This was like a dream come true. Never in all of Morgan's life did he imagine he would be bedding two women in the same room. Once his focus went back to the lovely knight, he found her unfastening her skirt and pulling it down to reveal a nice pair of white, frilly panties. Morgan stared at her voluptuous bare thighs before addressing the matter. "I-I don't know what to say. This all so sudden that I don't even know what to do."

"There's nothing to worry about, Morgan," said Lucina, sitting at a dim corner. She had a look of nervousness and thrill about her. “Tonight, we are here for your pleasure.”

"She's right, just enjoy the show." Cynthia moved her hands to her light blue uniform's buttons and unfastened each one before discarding the piece. He swallowed when he saw her ample cleavage wrapped tightly by a gorgeous white bra. They looked so heavy and ready to spill out that he was afraid her straps would snap at any moment. "Like what you see, Morgan? Don't worry, there's more."

The blue pig-tailed girl unclasped her bra at the front and let it slide down, revealing her incredible assets, mounds as perky as a freshly inflated ball. Cherry pink nipples adorned them, jutting out like a pair of buttons.

"He definitely loves your girls," commented Lucina with a distant voice.

"Hehehe." Cynthia giggled. She watched his cock pulse and come alive from the sight of her. It stood up without any help but a bit of inspiration. Grinning, she wrapped her palms around her breasts and squeezed them lightly. "So, how about it, Morgan? You like?"

"Y-yeah, absolutely." The young man nodded, carefully examining the bulbs pressed up against each other from her grasp. He could enumerate a number of contrasts between the two sisters. They were both skilled fighters, so their toned muscles could be glimpsed if one tried hard enough. But it was only Cynthia who had a distinct curve along the hips and an amazing rack he admired to no end.

Cynthia let go, and they each bounced once before settling their hefty weight down. She bent forward and freed herself from her panties' clutches. They fell to the floor, and she stepped out of them as she kneeled in front of the bed. “Come here, you stud. Let me have a closer look at that spear of yours.” She patted a spot on that side of the bed.

When presented by such an invitation, Morgan moved with haste and sat by the edge. His imposing shaft greeted her face with a small pulse. 

“Wow, you were packing a big one.” Cynthia leaned forward, her lips mere inches away from his tip. She looked towards Lucina, who was shifting uncomfortably on her chair. “Isn’t he great, Lucina?” She received a nod before she turned her attention back to Morgan. Her fingers curled around the base as she directed his head to her mouth. “No sense delaying further. Let’s see how you taste.” She licked the underside of his tip twice, sending a chill across his body and making him tremble, before descending her mouth in full, wrapping her lips around his cock. 

Morgan watched with bated breath as swallowed his cock whole. In an instant, she was bobbing up and down at an increasing pace while sucking his manhood. He couldn’t believe he was allowing his girlfriend’s sibling to get down on him, naked. He wasn’t complaining, but it was just so surreal. The muffled sounds she made while getting a good taste of his length was evidence that he wasn’t dreaming. “Hahh….Cynthia…” He bundled a part of the covers into his hands as tried to fight his squirming.

He spotted Lucina to the side, observing the raunchy act from afar. She seemed to be feeling restless, perhaps due to having another girl lay her hands on him.

Cynthia pulled back, slipping his member out, then started moving her hand that had been keeping it steady across the slippery skin. “So, how’d you like my fellatio, hm?” She asked giddily. “How does it compare to Lucina’s?”

“It’s incredible…” His throat rumbled as he tried to suppress his grunts. “And L-Lucina doesn’t like sucking me, so we don’t do it anymore.”

“Is that so?” Cynthia grinned. “That’s such a waste because I can suck you off any day of the week. I mean, yours is like a nice, big ol’ lollipop.”

Morgan couldn’t believe what he was hearing. Just the erotic tone of that proposition got his dick to twitch. Having a woman who would blow him anytime he wanted was a secret fantasy of his.

“Cynthia,” Lucina chirped. “I-I don’t think you should speak so brusquely.”

“Oh, don’t be so stuck up, Lucy.” Cynthia shot her sister a smirk. “If only you learned to loosen up, and I’m not just talking about your mouth mind you, you wouldn’t need to come to me to please your boyfriend.”

Lucina gritted her teeth at that, but it didn’t seem like she was mad, far from it. She was flushed with shame, and her sneaky hand was in between her thighs. Though it wasn’t obvious at first, her fingers had been prodding the closed lips of her pussy non-stop. If Morgan didn’t know any better, he would suspect she liked the taunts that her sister threw at her because the stern princess wouldn’t let a chance to prove her point slip away.

Cynthia looked at Morgan once again. “You’re far from coming yet, right?”

He nodded, although if she kept on sucking him, he’d be dangerously close.

“Good, try to last as long as possible because this is where the fun part begins.” She unlatched her grip on him and guided her hands to push her boobs up on top of Morgan’s lap. He stared in bewilderment as she parted them and put his cock in between those soft globes. The sensation tingled his nerves and got his entire body jerk from how incredible it felt. 

Her breasts pushing against his rod on all sides were nothing short of heavenly. He tightened his clutches on the bedsheets as he fought to last as long as possible. But when she leaned further against him, hugging his stiffness tightly with her assets while rapidly lifting them back and forth, his moans grew in volume.

As she gave him the best titjob of his life, she grinned at the “I bet Lucina can’t do this for you, huh? Not with her petite, little tits. Little Lucy over there is lacking in so many things.”

At first, Lucina had her legs tightly closed together, but now they were drifting apart, showing how fingers worked to jab her naked hole. Her other hand began massaging her chest over her robe while she was so engrossed in observing her sister’s lewd play. She was panting hard, turned on by being left out.

“What’s wrong, little Lucy?” Cynthia kept bouncing her boobs. “Envious you don’t have them this big?”

After watching Lucina getting herself off, Morgan couldn’t last any longer and stiffened his entire body.

“Wow!” Cynthia squealed as jets of cum flew before landing all over her. She took a sample from her cheek with her tongue and tasted his seed with a gleeful air about her. “Yummy! So this is what you taste like, Morgan. I envy my sister for getting to savor your jizz all the time.”

“That was incredible.” Morgan took a breather as he watched the younger sister clean herself up from her breasts to her face, enjoying the taste of his own load. “Cynthia, I want to repay the favor,” he said after recovering.

* * *

Lucina stared wide-eyed as Morgan laid down and Cynthia crawled on top of him. It was maddening to just sit there and watch while her own sister was enjoying herself with the man he loved. But, at this very moment, her pussy was as drenched as the ocean. As she kept moving her digits inside, she could feel overwhelming stickiness inside her tunnel that was the result of watching them. It was a whole new level of arousal she had never experienced before.

She let out a soft whimper as she watched Cynthia sit on Morgan’s face, arrogantly touting her influence over him. The way Cynthia smirked at her sent chills running down her spine and forced her to ravage her petite mounds more intensely. She had already unbuttoned the three buttons of her dress and inserted her hand right inside to feel up her skin. It didn’t take long before her sibling got descended and started lapping at his cock until his erection returned in full force. Cynthia moaned as she ground against Morgan’s face, and he latched onto her ass as he ate her out. 

Lucina moaned while feeling powerless and forced to listen to an orchestra of erotic sounds they were making. Cynthia was rolling her hips, pushing her wet pussy against Morgan, when she suddenly stopped sucking his cock and let out a lengthy mewl. Her entire body trembled as she came on Morgan’s face. She made a face full of bliss, converting all the tension in her body into sexual release. A moment later, she rolled off him and took heavy breaths. 

The pegasus knight watched as her partner’s manhood throbbed painfully. She giggled and reached down to stroke him. “Did my pussy taste that good?”

“Yeah, it was great.” Morgan took heavy breaths before reaching out to her and grabbing a handful of her soft chest.

“Did you hear that, Lucy?” Cynthia glanced briefly at her, and she tried to look neutral and unaffected. 

“Yeah, I heard it.” Lucina closed her legs, throwing glares of envy at her sister.

Cynthia smiled before putting all her attention on the young tactician. Lucina closed her eyes and focused on masturbating. A small crack opened up between her legs as she let her other hand stimulate her clit. Meanwhile, the two switched places and appeared completely preoccupied with each other.

“Mhmm...Morgan…” moaned Cynthia as she laid on her side with Morgan behind her, groping her tits quietly. “I want you inside me…”

Morgan gazed at Lucina worriedly, but all the older princess could do was to hesitate for a few seconds before nodding.

Soon, the two were moving around, standing on their knees.

“I got an idea.” Cynthia smiled as she got on all fours and reached out behind her. She spread her ass cheeks apart with a hand while looking back at the young tactician. “Why don’t you slam it right inside my ass? I’ve always wanted to try getting railed from my asshole since I heard all the girls talk about how great it feels.”

Morgan was jerking his hard-on while marveling at her wide rump. “I’ve always wanted to try anal, but I was always afraid Lucina might think me weird. And she’s never adventurous in bed anyway.” Lucina inhaled sharply from that comment, feeling a light stab in her chest that actually felt good. The pain actually felt better than her fingers. She was sure he said it intentionally to spite her even though it was hard to believe.

Cynthia laughed. “If it was me, I’d let you fuck me anywhere you want, you hot stud.” She slapped her ass one time. “Just stick it in already. How painful could it be?”

Lucina’s eyes widened and her nails bit into her chair’s wooden frame as Morgan complied with her sister’s request, advancing towards her upraised naked bum and guiding his cock to her puckered hole. Cynthia was looking back, spreading her legs, ready for him. Lucina could hear the wild thumping of her heart. She found it hard to believe that she was about to let her loved one do the deed with another woman. They could not turn back once she allowed them to continue further. It was her right to stand up now and steal him back, but a voice in the back of her mind was whispering to her to sit tight and stay quiet. After fighting with that voice for some time, she came to the conclusion that she needed to take responsibility for bringing her sister here and live up to her word. There was also Morgan. If he was enjoying the unique dynamic that her sister brought, then that was even more reason to sit still, even if it was humiliating and nerve-wracking.

As Morgan inserted the tip into the obscene hole, Lucina felt a pang of arousal course through her entire body. She felt her nipples grow stiff and her legs squirm from her boyfriend finally pushing his hips to bury his cock.

Despite Cynthia’s carefree words, anal was indeed painful. She nearly cried for the first few seconds before her grunts turned into sharp breaths. Morgan, too, appeared to have difficulty fitting his manhood in her tight hole. He had to spit on her anus just to make sure it was properly lubricated. Then a few moments later their grunts turned into loud, vocal moans.

“AHHH! YESSH! HAHH! HARDER, MORGAN! HA-HARDERR!” Cynthia’s entire body rocked as she pushed against the boy’s body, sheathing his entire cock inside her each time. Her nipples brushed against the bed from pushing her rear up.

“Oh gods, it feels so good, Cynthia!” Morgan had his grip on her hips as he pistoned her asshole, but it quickly traveled down to her breasts. His thrusts were mighty powerful, even more, when he did it with Lucina. Each collision sent a ripple through her soft bum. His face was desperate and thoroughly lost in the ecstasy of the knight’s asshole.

“Hahhhh! AHHH! This is the best!” Cynthia continued to slap her ass against his hips, not caring whether she looked like a whore. Her pigtails swung around each time her body rocked.

Lucina was afraid their voices might be heard by the neighboring homes but not as much as the fear she had of her boyfriend being stolen by her sister if this kept up. 

The two were just insatiable. They continued fucking in that same position for so long that Lucina could swear they were possessed. She was already sore from fingering herself that she wished for her own chance to feel his cock, but she knew Cynthia wouldn’t let her have it. It was their deal. 

A long cacophony of moans later, Morgan thrust one last time before he came inside her sister’s asshole. Cynthia buried her face against the sheets as she came as well. The two mewled in sync while Lucina was left to witness this debaucherous scene.

After they unlatched themselves from one another, Lucina noticed that Morgan’s cock quickly recovered. He sat back up and immediately put his attention on the sexy knight.

“Can we try another position?” Morgan was breathing less now, and Cynthia smiled at him and nodded. Lucina could hardly believe he was saying that. He never 

“Of course, anything for you, Morgan,” said the pig-tailed in a lascivious tone. “Because unlike someone, I’m open to anything you want.”

Morgan had her lie on her side facing Lucina as he propped one of her legs up to rest on his shoulder. He aligned his cock to her pussy and started thrusting. Lucina gasped while watching them moan. Her dress had already bunched up to her neck as she slid her fingers in and out of her soaking wet cunt. 

“Mhmmm…” Cynthia mewled from the slow thrusts. She grabbed one of her shaking tits and massaged it while looking at the boy without obvious affection in her eyes. “You’re even bigger than before.”

Morgan had wrapped his arms around her knee as a pivot, so she was stuck in that position until he was done with her. 

“Lucina is missing out,” Cynthia cooed. “Aren’t you going to let her have a turn?”

“She’s enjoying her time as a spectator, so maybe later.” Morgan laughed, aware of how much she had been turned on by the sight of the two in their sultry endeavor. She couldn’t deny it, though. He followed up with, “Plus, it’s so hot that my girlfriend is watching me fuck another girl. It’s thrilling!” 

Lucina, from the bottom of her heart, was happy that her love was enjoying himself. It gave her renewed energy to pick up her moans. 

The act lasted longer than their previous sessions. They changed positions twice before continuing their sex. Lucina had completely ditched her robe and watched them nude. She was making vocal gasps and grunts of her own, but they were completely ignored. She could feel her strength being drained as her arousal escalated with each position they took. 

“A-are you two nearly done?” Lucina asked after her fourth orgasm by her fingers.

“Just one more round,” replied Morgan, not looking her way and instead focused on the pig-tailed girl’s back as he took her from behind.

“Don’t be so impatient, Lucy.” Cynthia grinned as she tried to support herself with her arms. “I’m still feeling good from your boyfriend’s cock. Ahh!” Morgan slapped her ass. “Mhmm...yesss, babe. Drive that fat meat deep into my cunt. Make me your girl.”

Their pace quickened after a minute or two. Morgan had her lay on her back and pushed her knees close to her chest as he fucked her in a tight mating press. Morgan's hips moved at a steady pace, slamming deep into her sister's used hole. No matter how many times Lucina saw it, she never got tired. She could see his balls slapping against the knight each time his hips came crashing down.

Lucina could tell when he finally came as the two moaned to each other and kissed. Lucina felt weakness around her legs before she finished cumming once again.

Cynthia had a glazed look in her eyes once Morgan rolled. Sweat covered every inch of her body. "That was so amazing, Morgan." She sat and found their juices dribbling out of her, both Morgan and Cynthia’s. She had on an amused face as she spread her pussy lips apart. Lucina's gaze met her sister's after a moment. “Lucina, come here for a bit.”

She stood up, conscious of her nakedness in front of the two. Once she was at the foot of the bed, Cynthia edged closer, spreading her legs. “Morgan came so much. Wow! Could you clean this up for me?”

Lucina didn’t know what came over her to drop on her knees and place her hands on Cynthia’s thighs. Her beady eyes examined the thick dribbles coming out. The scent was overpowering, sending spikes of arousal in her. Her spine tingled and felt her pussy react, dripping thin lines onto her thighs. She pushed her head against her sister’s cunt, dragging her tongue against the warm fold and scooping thick oozes into her mouth. She heard Cynthia moan aloud. Morgan watched the deprave act with keen interest, which only turned her on even more, and her tongue slipped out the cunt and made its way to the small patch of hair past the clit. Cynthia’s hand grabbed a handful of her hair as she brushed her sibling’s clit.

She could say anything about the taste. Not only was she unable to think straight, but she was also enamored by the mere act of submission. Every drop and speck of cum she swallowed was drowning in her in bliss.

Once she had licked all over her sister’s sex, leaving behind nothing but spit across her supple skin, Cynthia smiled at her, rubbing her head. “Seems like you are a much better pussy eater, Lucy. We’re going to have so much fun from now on.”

“Sister…..” Lucina blushed, dirty cum stains soiling her face. “Please….let me do it with-”

“Uh uh.” Cynthia wagged her finger. “A deal’s a deal.”

That brought back Lucina to reality. The princess became a silent observer through the two’s bedding, not allowed to touch or be fucked, and she embraced the fact that she got off from it. The story of their debaucherous dynamic began from there.

**Notes for the Chapter:**

> I do monthly polls and stories. Feel free to check my profile for details.

**Author's Note:**

> Commission by Drakesorceror.
> 
> I do monthly polls and stories. Feel free to check my profile for details.


End file.
